This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 18 |
| 3 | 337 |
| 4 | 5994 |
| 5 | 121778 |
| 6 | 2518082 |
| 7 | 52655411 |
| 8 | 1103993538 |
| 9 | 23172461572 |
| 10 | 486537381066 |
| 11 | 10216717221605 |
| 12 | 214546979103002 |
| 13 | 4505458523356886 |
| 14 | 94614430060611570 |
| 15 | 1986901652087170519 |
| 16 | 41724924973226947986 |